Imaging findings of vertebral osteomyelitis caused by nontuberculous mycobacterial organisms Three case reports and literature review

Rationale: Prompt diagnosis of nontuberculous Mycobacterial (NTM) vertebral osteomyelitis is challenging, yet necessary to prevent serious morbidity and mortality. Here, we report 3 cases of vertebral osteomyelitis caused by NTM with imaging findings. Patient concerns: Case 1, a 58-year-old male patient, was admitted to our hospital because of the presence of a pulmonary mass for 6 months with cough and chest pain. Case 2, a 50-year-old male patient, had fever and cough for 3 years and was diagnosed with tuberculosis. Antituberculosis treatment was ineffective, accompanied by lymph node enlargement and osteosclerotic changes involving vertebral bodies. Case 3, a 66-year-old female patient, was admitted to our hospital with a mass on the top of her head for 1 month, which ruptured in the last 2 weeks. Diagnoses: Case 1: Sputum culture revealed Mycobacterium (M.) avium. Case 2: The final culture results of the lymph node biopsy samples were M. intracellulare. Case 3: Culture results of the sputum and pus from the abscess were M. gordon. We found sclerosing lesions in the spine in all 3 NTM patients, which were easily misdiagnosed as metastatic tumors. In 2 cases, there was bone destruction in the ilium with limbic sclerosis, and there were abscesses near the ilium and in front of the sacrum in 1 case. Interventions: Case 1 was transferred to other specialist hospital. Case 3 received surgical treatment for cranial lesions and abscess drainage. Case 2 and case 3 received targeted treatment for nontuberculous mycobacteria in our hospital. Outcome: The condition of case 1 was unknown. Recovery of case 2 was uneventful because of prolonged illness; however, inflammation gradually improved overall. Case 3 had no recurrence following surgical treatment. Lessons: In our 3 cases of NTM vertebral osteomyelitis, bone lesions were often misdiagnosed as bony metastases because of the presence of multiple sclerotic lesions. Diagnoses were challenging and delayed. It is important to consider osteomyelitis by NTM when disseminated osteosclerosis with or without osteolytic bone lesions is present in conjunction with continuous inflammatory symptoms and signs. Moreover, an open biopsy of the lesion should be performed for a definitive diagnosis.